Broccoli is a member of Brassica family like cauliflower and cabbage, its botanic name being Brassica oleraceae L. var. italica. 
Broccoli is native of the Mediterranean region and particularly grown in Italy for centuries. Indeed, it was considered as favorite vegetable by the Romans, who in the beginning ate a purple sprouting broccoli that turned green when cooked.
Broccoli has since been developed by selection and crossing to obtain varieties such as Calabrese (originating from the area of Calabria) or others broccoli varieties which have more and more improved qualities.
Broccoli is high in vitamins C, K, and A, as well as dietary fiber; it also contains multiple nutrients with potent anti-cancer properties, such as diindolylmethane and small amounts of selenium. A single serving provides more than 30 mg of Vitamin C and a half-cup provides 52 mg of Vitamin C. The di-indolylmethane found in broccoli is supposed to be a potent modulator of the innate immune response system with anti-viral, anti-bacterial and anti-cancer activity. Broccoli also contains the compound glucoraphanin, which can be processed into an anti-cancer compound sulforaphane, though the benefits of broccoli may be reduced if the vegetable is boiled more than ten minutes. A high intake of broccoli has been found to reduce the risk of aggressive prostate cancer. Broccoli consumption has also been shown to be beneficial in the prevention of heart disease.
Broccoli is usually boiled or steamed, but may be eaten raw and has become popular as a raw vegetable in hors d'oeuvre trays. Although boiling has been shown to reduce the levels of suspected anti-cancer compounds in broccoli, other preparation methods such as steaming, microwaving, lactic fermentation, and stir-frying have not been shown to reduce the presence of these compounds and so also constitute good alternative ways of cooking broccoli.
Broccoli is mostly marketed and consumed fresh; the part of the plant that is eaten is actually an undeveloped flower head hereinafter named head comprising many tiny buds crowded onto it.
Heads are harvested at maturity when they are an adequate size and have florets with a uniform green color.
A broccoli plant is considered good quality when the head is tight and compact, with a uniform dark green with as little yellowing as possible. A uniform head and floret color is a frequently requested trait in Broccoli. However, “green” head color results from the amount of sunlight reaching the crown of the head and florets. In fact, the yellowing is the result of a decline in chlorophyll (Deschene et al 1991), and is the result of insufficient sunlight exposure by the plant.
Current commercial broccoli varieties have an abundant and high leaf canopy that shades portions of head and this results in a yellowing of part of the head and florets (mainly around outer extremities of the harvested broccolis heads and may extend to individual florets at the center of the crown). This abundant amount of leaves is also an obstacle for the harvesting of the broccoli head.
The most common broccoli varieties grown around the world usually show an average to good vigor, a head height of about 40 to 50 cm above the ground and a leaf canopy height of at about 60 to 70 cm. The color of the head is green—from mild green to deep green—and the shape of the head is convex, i.e. round-shaped with the interior face of the circle oriented toward the ground. The stems of broccoli head are yellow or creamy due to the non exposure to the sunlight. The main stem of the plant holds secondary stems at the extremity of which the florets are arranged on a convex plane—lens-shaped—forming the head.
Broccoli is usually planted at a density of about 30 000 to 40 000 plants per hectare; while at higher density, up to 80 000 plants per hectare can be found. However, the higher the planting density is, the lower the size of the head.
The harvesting of the broccoli head needs to be done at the proper stage of maturity and uniformity of the head and florets. Furthermore, proper handling of the harvested heads and florets is of paramount importance to maintain good organoleptic (texture and color) and nutritional qualities. Indeed the thin buds comprised on the top of the florets constituting the head are very sensitive to crushing, the texture of the florets and stem may rapidly become soft and non appealing and the overall color of the product may also lose its attractiveness.
Due to the architecture of the plant, broccoli harvesting is done manually when the head has reached maturity. The main stem is cut and the head thus obtained is cooled and marketed as fresh product. This manual harvesting is expensive in term of labor cost and may represent up to 60% of the total labor costs for producing broccoli.
The use of mechanical harvesting solutions have been attempted but, because of the importance of leaf content and the deep burying of the head within those leaves, the jamming of the cutting equipment is an issue in the development of any mechanical equipment for harvesting broccoli.
Broccoli is mainly marketed fresh, as fresh heads. There is however a trend for individualized florets packed in bags in order to address a need for convenience and to provide the consumer with ready to eat or ready to cook vegetables.
This kind of packed fresh broccoli florets allows the consumer to cook broccoli conveniently without the need to clean broccoli heads, to cut florets one after the other and eventually to dispose of non-edible broccoli parts.
However, the cost of the processing of broccoli heads for producing individualized florets after harvesting is a serious issue. Indeed, the compactness and the arrangement of the florets forming the head and the convexity of that head make necessary either to manually cut and prepare the florets or to use specifically designed equipment in order to obtain those individualized florets. Moreover, in the current existing broccoli varieties, the uniformity of the florets obtained after processing of the head is not always satisfactory because the secondary stems of the head holding the florets do not have the same length nor the same width and therefore there is a big heterogeneity in the size and caliber of the obtained florets. The length of the secondary stems holding the florets is not uniform and leads to heterogeneous assortment of broccoli florets.
Broccoli is also increasingly marketed as frozen, mainly in the form of individualized florets, either alone or in combination with other vegetables in ready to cook mixes. In those cases as well, there is a need to handle and process the broccoli heads after harvesting as quickly as possible in order to preserve all the organoleptic qualities of the product. Once harvested, the broccoli heads are transported to the freezing factory, then the heads are cleaned, and the florets are cut-out thanks to a specific machine. The thus obtained florets are separated according to their size, the ones that are not conforming to the required standards are usually discarded and the ones of suitable size are kept for bleaching and freezing. The obtained byproducts—inadequate size florets—are usually made into purée for example; however there is a drop in price for this type of byproduct as compared to the calibrated florets used for freezing.
EP1597965 discloses broccoli plant suitable for mechanical harvesting that is characterized by the fact that the head of the broccoli plant is higher than the leaf canopy and furthermore that the plant does not comprise leaves having a surface area greater than about 30 square centimeters within 25 centimeters of the crown.
WO2007062009 discloses a broccoli plant having heads with detached florets arranged at the extremity of elongated secondary stems supporting said florets.
While both documents describe a broccoli plant with either exerted or detached florets, these broccoli plants are not completely suited for mechanical harvest and/or processing of individualized florets. Indeed, the broccoli plant described in EP1597965 exhibits a tight arrangement of the florets of the exerted head, an additional mechanical or manual processing of the obtained head is still necessary in order to easily obtain individualized florets.
Regarding the broccoli plant described in WO2007062009, while the florets are allegedly uniformly green and individualized, they cannot be harvested mechanically and still require manual harvesting, floretting (separation of florets from the harvested head) and trimming that does not contribute to save costs associated with the cultivation of plant suited for production of individualized florets, either for the fresh cut industry or for the frozen industry.
As an example, Tenderstem® refers to uniformly green broccoli sprouts type with an elongated stem. These products come from a variety of broccoli plant which, after cutting of the main head, produces a plurality of secondary stems with small heads at their top by sprouting. These secondary stems do not grow at the same time nor at the same speed. These sprouts need to be harvested by hand, almost one by one, and it is necessary to make a plurality of harvests over a slot of several days. All these harvesting constraints are detrimental from an economical point of view and constitute a limiting factor to the development of this particular broccoli type plant.
There is still a need for broccoli plants that produce head and/or florets that can be harvested and processed with the minimum hand-labour input in order to minimize the costs associated with the harvesting and/or processing of those heads and/or florets, particularly for the manufacture of individualized florets. The present invention aims at solving this problem and is addressing the need of providing a broccoli plant that produces a head that can be harvested by machine and florets that can also be harvested and/or processed by machine with minimal hand labor.